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<h4> Statistical testing of images and time courses </h4>
<hr>
<p><b>Two Sample t-test of Component Images</b></p>
 <p>Two sample <i>t</i>-test can be used to compare a component image between 
	subjects or sessions. For example for a particular component image session 1 
	can be treated as group1 and session 2 as group2. You can use these images 
	in SPM to do two sample <i>t</i>-test (<a href="icatb_references.htm">[3]</a>, 
	pp 12-14).</p>
 <p><b>Regression Parameters</b></p>
        <p>After performing temporal sorting, the regression parameters are 
		saved in a file with suffix &quot;regression.txt&quot;. This file can be quite 
		useful in performing statistical tests to evaluate the task-relatedness 
		of the components or to perform tests between components or groups. The 
		text&nbsp; file contains a number for each component, regressor, subject 
		and session (Table 1). The numbers represent the fit parameter from the 
		regression. In order to use these numbers it is important to scale the 
		ICA data. For example, if 10 subjects were analyzed with ICA and two 
		regressors were used to sort, then one can test the degree to which the 
		average amplitude of group 1 was greater than the average amplitude of 
		group 2 by computing a two-sample t-test between the 10 parameters for 
		group 1 and the 10 parameters for group 2. A separate test can be done 
		for each component and the component which show a significant difference 
		can be determined.</p>
        <p class="style1"><b>Table 1:</b> Table shows two sorted components 
		parameters. Regression values for each component are shown followed by 
		the beta weight of each condition with the ICA time course.</p>
        <center>
        <table border="2">
          <tr>
            <td width="33%">Component Numbers</td>
            <td width="33%">14 </td>
            <td width="34%" >13</td>
          </tr>
          <tr>
            <td width="33%" >Regression Values</td>
            <td width="33%" >0.82740899</td>
            <td width="34%" >0.74477757</td>
          </tr>
          <tr>
            <td width="33%" >Subject 1 Sn(1) left*bf(1)</td>
            <td width="33%" >-0.052490765</td>
            <td width="34%" >1.6484661</td>
          </tr>
          <tr>
            <td width="33%" >Subject 1 Sn(1) right*bf(1)</td>
            <td width="33%" >1.4887159 </td>
            <td width="34%" >0.13184605</td>
          </tr>
          <tr>
            <td width="33%" >Subject 2 Sn(1) left*bf(1)</td>
            <td width="33%" >0.12544365</td>
            <td width="34%" >1.0076309</td>
          </tr>
          <tr>
            <td width="33%" >Subject 2 Sn(1) right*bf(1)</td>
            <td width="33%" >1.6412895</td>
            <td width="34%" >0.75554373</td>
          </tr>
          <tr>
            <td width="33%" >Subject 3 Sn(1) left*bf(1)</td>
            <td width="33%" >-0.35264506</td>
            <td width="34%" >1.5612781</td>
          </tr>
          <tr>
            <td width="33%" >Subject 3 Sn(1) right*bf(1)</td>
            <td width="33%" >1.3959309</td>
            <td width="34%" >-0.0077817872</td>
          </tr>
        </table>
        </center>
      <p> &nbsp;We have now provided
		<a href="icatb_stats_on_beta_weights.htm">GUI</a> for doing statistics 
		on time courses (beta weights) under 
		<a href="icatb_getting_started.htm">Utilities</a> drop down box. </p>
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